New northwest Oregon tsunami maps show less high ground for refuge than thought

View full sizeTsunami warning signs are a common sight in communities along the Oregon coast.Benjamin Brink/The Oregonian

GEARHART, Ore. — New maps show there's less high ground than previously thought for refuge from the most serious earthquake and tsunami projected along Oregon's northwest coast, leaving city officials unsettled.

Oregon geology experts have compiled the maps using laser-based remote sensing technology and have been showing them to city officials at council meetings.

They are to be released publicly on Tuesday, the Daily Astorian reported. That's to be followed later this month by a series of community rallies to encourage preparedness.

In Gearhart, a city of about 1,500 south of Astoria, Mayor Dianne Widdop said she couldn't sleep after hearing what the maps showed: In the biggest of tsunamis, Gearhart residents wouldn't have anywhere they could be assured of safety.

Questioned about one part of town, she used T-shirt sizes to describe the most serious tsunamis.

"I can't sugarcoat it," she said. "It's dire if (the tsunami) is an XXL. There will be a lot of fatalities in this area."

A key feature of tsunami planning along the coast has been identifying assembly areas on high ground and marking routes for residents to get there quickly, preferably afoot since traffic is expected to be disrupted.

In Warrenton, Commissioner Mark Baldwin reviewed the new maps and noted that while two refuge areas continued to be marked as above the highest expected water marks, another wasn't.

"The grade school's gone," he said.

In Astoria, Deputy Police Chief Brad Johnston said the new mapping "changes the paradigm for Astoria related to tsunamis. Astoria never had to worry about significant inundation zones, and now we've started that conversation in a way we never had to before."

When the Gearhart city administrator, police chief and fire chief got their first look at the new maps, they worried that residents wouldn't even try to reach high ground if the map didn't show something. So the state designated two "optional high ground assembly" areas, something that hadn't been done anywhere else.

One is a strip of ground by the local golf course that would be above water in an estimated 95 percent of tsunamis, and another is a narrow strip of ground that would be only a potential oasis amid the tsunami waters.